Field of the Invention
The present invention relates to a display device. In particular, the present invention relates to a display device having a sub-pixel array structure which can have a high resolution and improve an aperture ratio.
Discussion of the Related Art
An organic light emitting diode display (OLED) device displays images using organic light emitting diodes as self-luminescent elements. An OLED device is a next generation display device having excellent brightness and color purity.
The OLED device includes a plurality of sub-pixel groups using red, green and blue sub-pixels and displays various color images. The red, green and blue sub-pixels can be arranged in various types of sub-pixel array structures including a stripe type, a mosaic type, and a delta type.
Sub-pixels arranged in the stripe type include same color sub-pixels arranged in the same column. Sub-pixels arranged in the mosaic type include red, green and blue sub-pixels arranged alternately in a row direction and a column direction. Sub-pixels arranged in the delta type include red, green and blue sub-pixels arranged alternately in a zigzag form.
FIG. 1 is a view illustrating a sub-pixel array structure including a sub-pixel group including first to third sub-pixels according to the related art. Referring to FIG. 1, a sub-pixel array structure 10 includes sub-pixel groups 15 including a first sub-pixel 11 positioned on a first column, a second sub-pixel 12 on a third column and a third sub-pixel 13 positioned on a second column. The sub-pixel groups 15 are arranged in two columns and two rows.
The first sub-pixel 11 emits red (R) light, the second sub-pixel 12 emits blue (B) light, and the third sub-pixel 13 emits green (G) light. The first to third sub-pixels 11 to 13 are included in one pixel. The first to third sub-pixels have the same area. A driving portion to operate each of the first to third sub-pixels 11 to 13 is located in each of the first to third sub-pixels 11 to 13. The driving portion occupies a certain area of each sub-pixel.
FIG. 2 is a view illustrating a sub-pixel array structure achieving a high resolution by increasing a number of first to third sub-pixels included in a sub-pixel group of FIG. 1 by four times according to the related art. Referring to FIG. 2, the sub-pixel array structure 20 includes sub-pixel groups 25, each including a first sub-pixel 21 positioned in a first column, a second sub-pixel 22 positioned in a third column and a third sub-pixel 23 positioned in a second column. The sub-pixel groups 25 are arranged in four columns and four rows. The sub-pixel array structure 20 of FIG. 2 is four times the number of sub-pixel groups of the sub-pixel array structure 10 of FIG. 1.
The first sub-pixel 21 emits red (R) light, the second sub-pixel 22 emits blue (B) light, and the third sub-pixel 23 emits green (G) light. The first to third sub-pixels 21 to 23 include one pixel. The first to third sub-pixels have the same area. The driving portion to operate each of the first to third sub-pixels 21 to 23 is located in each of the first to third sub-pixels 21 to 23. Each of the first to third sub-pixels 21 to 23 has a quarter of an area of each of the first to third sub-pixels 11 to 13 of FIG. 1. Because an amount of reduction in an area of the driving portion is limited, an aperture ratio of the sub-pixel array structure 20 having a high resolution is greatly reduced. To increase a level of brightness in order to compensate for the reduced aperture ratio, a power consumption increases.